Archaeology can provide two bodies of information relevant to the understanding of the evolution of human cognition – the timing of developments, and the evolutionary context of these developments. The challenge is methodological. Archaeology must document attributes that have direct implications for underlying cognitive mechanisms. One example of such a cognitive archaeology is found in spatial cognition. The archaeological record documents an evolutionary sequence that begins with ape-equivalent spatial abilities 2.5 million years ago and ends with the appearance of modern (...) abilities in the still remote past of 400,000 years ago. The timing of these developments reveals two major episodes in the evolution in spatial ability, one, 1.5 million years ago and the other, one million years later. The two episodes of development in spatial cognition had very different evolutionary contexts. The first was associated with the shift to an open country adaptive niche that occurred early in the time range of Homo erectus. The second was associated with no clear adaptive shift, though it does appear to have coincided with the invasion of more hostile environments and the appearance of systematic hunting of large mammals. Neither, however, occurred in a context of modern hunting and gathering. Key Words: Archaeology; evolution; Homo erectus; spatial cognition; symmetry. (shrink)

Infant facial characteristics may affect discriminative parental solicitude because they convey information about the health of the offspring. We examined the effect of Fetal Alcohol Syndrome (FAS) infant facial characteristics on hypothetical adoption preferences, ratings of attractiveness, and ratings of health. As expected, potential parents were more likely to adopt “normal” infants, and they rated the FAS infants as less attractive and less healthy. Cuteness/attractiveness was the best predictor of adoption likelihood.

Infant facial characteristics may affect discriminative parental solicitude because they convey information about the health of the offspring. We examined the effect of Fetal Alcohol Syndrome (FAS) infant facial characteristics on hypothetical adoption preferences, ratings of attractiveness, and ratings of health. As expected, potential parents were more likely to adopt “normal” infants, and they rated the FAS infants as less attractive and less healthy. Cuteness/attractiveness was the best predictor of adoption likelihood.

We propose a coevolutionary model of secrecy and stigmatization. According to this model, secrecy functions to conceal potential fitness costs detected in oneself or one’s genetic kin. In three studies, we found that the content of participants’ distressing secrets overlapped significantly with three domains of social information that were important for inclusive fitness and served as cues for discriminating between rewarding and unrewarding interaction partners: health, mating, and social-exchange behavior. These findings support the notion that secrecy functions primarily as a (...) defense against stigmatization by suppressing information about oneself or one’s kin that evolutionarily has been devalued in mating and social exchange. (shrink)

Although facial features that are considered beautiful have been investigated across cultures using the framework of sexual selection theory, the effects of head hair on esthetic evaluations have rarely been examined from an evolutionary perspective. In the present study the effects of six hair-styles (short, medium-length, long, disheveled, knot [hair bun], unkempt) on female facial attractiveness were examined in four dimensions (femininity, youth, health, sexiness) relative to faces without visible head hair (“basic face”). Three evolutionary hypotheses were tested (covering hypothesis, (...) healthy mate theory, and good genes model); only the good genes model was supported by our data. According to this theory, individuals who can afford the high costs of long hair are those who have good phenotypic and genetic quality. In accordance with this hypothesis, we found that only long and medium-length hair had a significant positive effect on ratings of women’s attractiveness; the other hairstyles did not influence the evaluation of their physical beauty. Furthermore, these two hairstyles caused a much larger change in the dimension of health than in the rest of the dimensions. Finally, male raters considered the longer-haired female subjects’ health status better, especially if the subjects were less attractive women. The possible relationships between facial attractiveness and hair are discussed, and alternative explanations are presented. (shrink)

The development of robots that closely resemble human beings can contribute to cognitive research. An android provides an experimental apparatus that has the potential to be controlled more precisely than any human actor. However, preliminary results indicate that only very humanlike devices can elicit the broad range of responses that people typically direct toward each other. Conversely, to build androids capable of emulating human behavior, it is necessary to investigate social activity in detail and to develop models of the cognitive (...) mechanisms that support this activity. Because of the reciprocal relationship between android development and the exploration of social mechanisms, it is necessary to establish the field of android science. Androids could be a key testing ground for social, cognitive, and neuroscientific theories as well as platform for their eventual unification. Nevertheless, subtle flaws in appearance and movement can be more apparent and eerie in very humanlike robots. This uncanny phenomenon may be symptomatic of entities that elicit our model of human other but do not measure up to it. If so, very humanlike robots may provide the best means of pinpointing what kinds of behavior are perceived as human, since deviations from human norms are more obvious in them than in more mechanical-looking robots. In pursuing this line of inquiry, it is essential to identify the mechanisms involved in evaluations of human likeness. One hypothesis is that, by playing on an innate fear of death, an uncanny robot elicits culturally-supported defense responses for coping with death’s inevitability. An experiment, which borrows from methods used in terror management research, was performed to test this hypothesis. [Thomson Reuters Essential Science Indicators: Fast Breaking Paper in Social Sciences, May 2008]. (shrink)

Early psychosocial stress (e.g., parental divorce, abuse) is conjectured to place individuals on a developmental trajectory leading to earlier initiation of sexual activity, earlier reproduction, and having more sex partners than those with less early psychosocial stress. But does it also affect an individual’s mate choice? The present study examined whether early psychosocial stress affects preferences and dislikes for opposite-sex faces varying in masculinity/femininity, a putative indicator of mate quality, in premenopausal women (58 with a natural cycle, 53 pill-users) and (...) 196 men. No significant three-way interactions were found when women selected the most or least preferred face with participant group (natural cycle, pill), conception risk (low, high), and early psychosocial stress (low, high) as between-subjects factors. Early psychosocial stress did not affect men’s face preferences when selecting the most preferred face. However, men with high early psychosocial stress disliked masculine faces significantly more so than men with low early psychosocial stress. Overall it was concluded that early psychosocial stress does not affect mate choice with the exception that men with high early psychosocial stress were more likely to dislike masculine female faces. It was suggested that men with high early psychosocial stress may dislike masculine female faces because they have nothing to gain from associating with women with such faces. (shrink)

Although scientific interest in facial attractiveness has developed substantially in recent years, few studies have contributed to our understanding of the ontogeny of facial preferences. In this study, attractiveness of 30 male faces was evaluated by four female groups: girls at puberty, nonpregnant and pregnant young women, and middle-aged women. The main findings are as follows: (1) Preference for sexy-looking faces was strongest in young, nonpregnant women. (2) Biologically more mature girls displayed more adultlike preferences. (3) The intragroup consistency for (...) postmenopausal women was relatively low. (4) In terms of the preference pattern, pregnant women were more similar to perimenopausal women than they were to their nonpregnant peers. (5) Preference for youthful appearance decreased with the age of the women. I argue that the life history of female preferences for male faces is, to a large extent, hormone-driven and underpinned by a set of evolutionary adaptations. (shrink)

Sociobiologists and feminists agree that men in patriarchal social systems seek to control females, but sociobiologists go further, using Darwin’s theory of sexual selection and Trivers’s ideas on parental investment to explain why males should attempt to control female sexuality. From this perspective, the stage for the development under some conditions of patriarchal social systems was set over the course of primate evolution. Sexual selection encompasses both competition between males and female choice. But in applying this theory to our “lower (...) origins” (prehominid ancestors), Darwin assumed that choices were made by essentially “coy” females. I argue here that female solicitation of multiple males (either simultaneously or sequentially, depending on the breeding system) characterized prehominid females; this prehominid legacy of cyclical sexual assertiveness, itself possibly a female counter-strategy to male efforts to control the timing of female reproduction, generated further male counter-strategies. This dialectic had important implications for emerging hominid mating systems, human evolution, and the development of patriarchal arrangements in some human societies. For hominid males who will invest in offspring, there would be powerful selection for emotions, behaviors, and customs that ensure them certainty of paternity. The sexual modesty that so struck Darwin can be explained as a recent evolved or learned (perhaps both) adaptation in women to avoid penalties imposed by patrilines on daughters and mates who failed to conform to the patriline’s prevailing norms for their sex. Other supposedly innate universals, such as female preferences for wealthy husbands, are also likely to be facultative accommodations by women to constraints set up when patrilines monopolized resources needed by females to survive and reproduce, and passed on intergenerational control of these resources preferentially to sons. (shrink)

Evolutionary psychology is a science in the making, working toward the goal of showing how psychological adaptation underlies much human behavior. The knee-jerk reaction that sociobiology is unscientific because it tells just-so stories has become a common charge against evolutionary psychology as well. My main positive thesis is that inference to the best explanation is a proper method for evolutionary analyses, and it supplies a new perspective on the issues raised in Schlinger's (1996) just-so story critique. My main negative thesis (...) is that, like many nonevolutionist critics, Schlinger's objections arise from misunderstandings of the evolutionary approach.Evolutionary psychology has progressed beyond telling just-so stories. It has found a host of ingenious special techniques to test hypotheses about the adaptive significance and proximate mechanisms of behavior. Naturalistic data using the comparative method combined with controlled tests using statistical analyses of data provide good evidence for a variety of hypotheses about behavioral control mechanisms — whether in nonhumans or in humans. For instance, the work of Gangestad and Thornhill on evolved mate preferences and fluctuating asymmetry of body type (FA) is a model of success. As the quantity and quality of evidence increase, we are entitled not just to regard such evolutionary hypotheses as preferable, but also as true. Such studies combine to show that the best explanation of the psychic unity of humankind — common patterns across societies, history, and cultures exposed by evolutionists — is the gendered, adapted, evolved species-typical design of the mind. (shrink)

This study explores the evolutionary-based hypothesis that facial attractiveness (a guiding force in mate selection) is a cue for physical fitness (presumably an important contributor to mate value in ancestral times). Since fluctuating asymmetry, a measure of developmental stability, is known to be a valid cue for fitness in several biological domains, we scrutinized facial asymmetry as a potential mediator between attractiveness and fitness. In our sample of young women, facial beauty indeed indicated physical fitness. The relationships that pertained to (...) asymmetry were in the expected direction. However, a closer analysis revealed that facial asymmetry did not mediate the relationship between fitness and attractiveness. Unexpected problems regarding the measurement of facial asymmetry are discussed. (shrink)

I offer the first sustained defence of the claim that ugliness is constituted by the disposition to disgust. I advance three main lines of argument in support of this thesis. First, ugliness and disgustingness tend to lie in the same kinds of things and properties (the argument from ostensions). Second, the thesis is better placed than all existing accounts to accommodate the following facts: ugliness is narrowly and systematically distributed in a heterogenous set of things, ugliness is sometimes enjoyed, and (...) ugliness sits opposed to beauty across a neutral midpoint (the argument from proposed intensions). And third, ugliness and disgustingness function in the same way in both giving rise to representations of contamination (the argument from the law of contagion). In making these arguments, I show why prominent objections to the thesis do not succeed, cast light on some of the artistic functions of ugliness, and, in addition, demonstrate why a dispositional account of disgustingness is correct, and present a novel problem for warrant-based accounts of disgustingness (the ‘too many reasons’ problem). (shrink)

In every known human society, some kind—usually many kinds—of art is practiced, frequently with much vigor and pleasure, so that one could at least hypothesize that “artifying” or “artification” is a characteristic behavior of our species. Yet human ethologists and sociobiologists have been conspicuously unforthcoming about this observably widespread and valued practice, for a number of stated and unstated reasons. The present essay is a position paper that offers an overview and analysis of conceptual issues and problems inherent in viewing (...) art and/or aesthetics as adaptive, and it presents a speculative account of a human behavior of art. (shrink)

Two studies examined the link between social dominance and male waist-to-hip ratio (WHR). Groups of four men interacted in a leaderless group discussion. In both studies, men with higher WHRs (associated with current and long-term health status) were rated by other group members as behaving more leader-like when an observer was present, and rated themselves as being more assertive. In Study 2, men with higher WHRs were rated by independent observers as behaving more dominantly, but only when the evaluator was (...) present. These results are discussed in terms of evolutionary models of health, attraction, and intrasexual competition. (shrink)